GENEVA, March 2 (Reuters) - Automakers will need broad, political support to come up with a common standard for plugs and infrastructure for electric cars if they are to become a convenient option for consumers, they said.

Auto executives gathered at the Geneva auto show this week said a lack of standardisation could become an issue when the zero-emission cars start to sell in larger numbers by mid-decade, as they compete with low-emission hybrids.

“Standardisation and harmonisation is a big critical issue in Europe,” said Michel Gardel, vice president at Toyota Motor’s (7203.T) European operations. “Because for now if we travel from Denmark to Italy you have to change your plug four times.”

Reaching a common industrial policy for anything is a headache in Europe, where governments prioritise domestic interests, sometimes at the expense of regional harmony and convenience for consumers.

That could be a problem for electric cars when they eventually become capable of going longer distances, for cross-border travel.

“What we’re trying to do as an industry -- and it’s tough, because there are a lot of competitive issues -- let’s make sure that we have one plug,” Carlos Ghosn, head of the Renault-Nissan alliance, told fellow participants at a World Economic Forum session in Davos earlier this year.

“Because if consumers start to say, ‘If I move from one country to the other and I have a different plug, a different device, it’s a problem. For the suppliers it’s a problem. For the electricity companies it’s a problem,” he said, according to a transcript of the closed-door session seen by Reuters.

Executives at Renault (RENA.PA) and Nissan (7201.T) -- which together want to lead the electric vehicle (EV) field -- downplayed any immediate problem for electric cars, saying they expected drivers to use them for commuting and short-distance driving, plugging in mostly at their home charging stations.

“It’s not a show stopper,” Simon Thomas, senior vice president of Nissan’s European operations, told Reuters in Geneva on Wednesday. “At the worst, it’s a minor inconvenience.”

Even without a common standard, Thomas said, consumers would most likely have an extra cost of just a few hundred euros to buy a different cable to plug in.

“It’s not optimal in that all the car makers would like to have one standard everywhere in the first European countries that are launching (EVs). But everyone is working on it,” said Beatrice Foucher, product head at Renault.

Executives expect any decision on standardisation to be at least two years away, when Europe’s top automaker, Volkswagen AG (VOWG_p.DE), is planning to enter the EV market in earnest.

At the annual Geneva auto show, Renault is showcasing the Kangoo Van Maxi Z.E. electric commercial vehicle, while at the next stand, partner Nissan unveiled the ESFLOW, a sleek zero-emission sports car concept equipped with an electric motor in each of the two rear wheels.

Speaking of European industrial policy in general, Ford (F.N) Europe CEO Stephen Odell said flatter regulations would go far in helping automakers cut costs, which in turn would help them keep factories open and jobs secure.

“It is a conversation that I have with any politician who will listen,” Odell said. “In the end, unless you have an industrial policy, you’re going to struggle in the global economy.”

Having one standard in the vast Chinese market was a big advantage that could help EVs spread fast in China, the head of Warren Buffett-backed electric car maker BYD Co (1211.HK) said.

“We expect approval for standardisation in China in the first half of this year,” BYD Chairman Wang Chuanfu told Reuters in Geneva. He added that a lead in EV technology gives BYD an opportunity to enter the European market, where he said competing in the mature internal combustion engine model would be tough.

HURDLE OR HICCUP?

Proponents of competing technology used the lack of standardisation to play up their own approach.

“With plug-in hybrid cars, you don’t have that problem because when you run out of electricity, the gasoline engine will kick in,” said Takeshi Uchiyamada, head of R&D at Toyota.

“I think that a day when we see hybrids making up more than 30 percent of cars sold in Japan, the U.S. and Europe is no longer a pipe dream,” he said.

Nissan Executive Vice President Colin Dodge begged to differ.

“Pure EV will have a big market. Plug-in hybrids will have a reasonably sized market for large cars, and internal combustion engines will always exist,” he said. Dodge added that Nissan expected to deliver 5,000-6,000 EVs in Europe in the business year ending in March 2012.

The head of Japan’s Mitsubishi Motors (7211.T), which put the world’s first mass-produced electric car, the i-MiEV, on the road in 2009, said EVs were already setting milestones in Europe.

In Norway, President Osamu Masuko said, the i-MiEV became the single-best selling model in the microcar segment -- inclusive of petrol and diesel cars -- for the first time this January, and probably again last month.